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Re: (meteorobs) Plotting: Three Stooges Method

Most of my thoughts on plotting have already been addressed.  So this
is perhaps more for emphasis.  Also bear in mind I plot telescopic
meteors.

1) I can't use string or ruler (I'd prefer string if I plotted visual
meteors).  Instead I memorize the path of the meteor, using two pairs
of stars which bracket the path.  The pairs should as far apart as
possible, but that's not always feasible.  It's better to to choose
pairs which you are confident the meteor passed between.

I replay the meteor and mentally note its path.  For instance, it
passed midway between the first pair and a third of the way from the
upper to the lower of the other pair.  Only once I have that memorized
do I think about the magnitude and speed.  After some experience those
come naturally.  It's the path that's the easiest to get wrong and so I
concentrate on that.  When practised this doesn't take long.  However,
in unfamiliar fields in the Milky Way, it can be quite challenging.
Plotting become quicker once you know the star patterns.

Once I have the meteor data memorized, I then switch on my red torch
to plot the meteor, record the details, and then the time.

2) At first I was mystified where the path length, arms and fists,
came in.  That must be to estimate the meteor speed in degrees per
second.  It's not needed for plotting itself.  Just draw the meteor
path where you saw it against the stars.  Gaining that familiarity
takes time.  It was a strange and humbling during a recent Perseid
session to feel lost in the south because of the angle of certain
constellations---I'd never seen Cetus rising vertically---the number
of faint stars, and those obscure southern constellations.

Kim, I'd heartily recommend H.A.Rey's "A New Way to See the Stars".
It will teach you the constellations very quickly.  One other
suggestion, try to learn a constellation a night.  By learn I mean
knowing their names, Arabic or Greek letter to say about mag. 3.5.  I
must admit that I've forgotten many now, but knowing my way around the
sky was invaluable during my early visual meteor watches.

3) As I sit upright, I normally have a jacket with big pockets to hold
lots of spare pencils, erasers, etc.  I left that in the UK, so I might
add some pockets to my large clipboard.  Besides a hand-held torch, I
have a clip-on red swivle LED light.  The button is tricky, but the
batteries last longer.  I also place a folding chair beside me
to store spares, Norton's Star Atlas etc.  It's also handy to put
the clipboard on too when getting in and out of the sleeping bag.
There's also a platform within the tripod I sometimes use.  So mine's
more of a three stools method.

On windy nights I also have spare clips to hold the report sheets and
charts down.  Fluttering charts make plotting difficult.

4) If you use a clear ruler, I recommend putting some white or
reflective tape at one end, to make it easier to find if it goes
`overboard'.  I like to tie one pencil to the clipboard to reduce
the chances of a losing the pencil.

5) I do have a talking watch.  However, it was a going-away present
bought in Japan.  Thus it has a Japanese voice doing an impression of
an American accent, and it doesn't have 24hr.  So I've not used it.
The clocks for the blind I looked at in Britain were all too bulky.
I'd appreciate details of the small clock you use Cathy.  I tie my
watch around the top of a tripod leg with the face towards me.
Looking at watch adds a little dead time.

6) The traditional night food in Britain was "Jaffa Cakes".  Here I
have to make do with chocolate-chip/macadamia nut cookies and water.

Kim, stick at it, and it will become a lot easier.

One last thing.  It's a gnomonic projection, not gnomic.

Off now to observe up Mauna Kea. (-:

Malcolm

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